1. Field of the Invention
This invention relates to filtering devices for separating a liquid-particulate mixture into distinct portions and more particularly to a flat bed type filter in which separation may be advanced by applying a pressure to the liquid-particulate mixture.
2. Description of the Prior Art
Filter devices for separating foreign matter from a liquid flow are well known. Such devices may take a number of forms depending on the type of operation, i.e. batch or continuous, the percentage concentration of the foreign matter, the physical nature of the foreign matter, and the type of controls which may vary from fully manual to fully automatic.
One well known type of filter device is the flat bed filter where a batch of a liquid-foreign matter mixture is pumped into a filter chamber having a filter media bottom. Depending on the particle size of the foreign matter, the filter media bottom can vary from an open grid panel to provide straining to a filter cloth precoated with diatomaceous earth for retaining matter of a few microns in size. Usually the filter cloth is attached to a conveying device which allows the filter cloth to be readily withdrawn from the filter after use. A movable cover, which seals the mixture in the filter device during operation, is raised to allow this movement. Pressures as high as 20 psi are applied to the mixture to promote liquid flow.
The flat bed type filter offers the user a relatively simple device to operate, a large filter media area to allow high through-put, and flexibility to meet varying operating conditions.